OK, as far as lighting goes, I'd highly recomend the $20 27watt Home Depot desk lamp. It's inexpensive, efficiant, bright, easy to settup/use, easy to procure, and even stylish... What more could you wnat?
You can use it as-is, as seen here on Nano nano's new nano (yeah, that's a lot of "n"s):
Or you could get the lamp, then promply gut it and make it into a retrofit for a custom hood (with a little extra work and a few extra parts), like I've done:
For carbon suplementation, you have the option of ADA mini CO2 ssytem (beautiful and functional, but too rich for my budget), DIY yeast system (too mesy, unpredictable, and high maintenance in my experience), a DIY paintball cylinder system (too much work and cost to justify, IMHO), or you could skip CO2 altogether, and go with Sea Chem Fluorish excel (easiest, most cost effective method of carbon supplementation for a nano IMHO). Just some ideas.
Oh, and may I suggest you consider a mini canister filter instead of the HOB? I recently got the ZooMed 501 mini canister
, and love it. There's also the TOM Rapids Mini Canister, but I've heard a few complaints - no personal experience with it. Your call.
Well, that's my two cents (plus tip).